Online Pattern Catalogs• Alien life - Pattern collections focusing on Life-like cellular automata other than Conway's Game of Life itself• Game of Life Object Catalogs at Pentadecathlon - contains most small still lifes, oscillators and spaceships• Mark D. Niemiec's Life Page - contains lots of well-known patterns, sorted by either name, glider synthesis, size, or type (via archive.org)

Downloadable Computation and/or Search Software• Catalyst v1.0 by Gabriel Navasch - Finds ways of modifying the evolution of an input pattern by placing catalysts that react with it, by a backtracking search. Written in C++.• CatForce by Michael Simkin - fast brute-force testing of arrangements of potential catalysts for signal-processing reactions. Written in C, based on the LifeAPI library.• CollisionsSearch v 0.1a by Sergei Petrov (Guam) - finds arrangements usually of small Spartan or near-Spartan objects, with various constraints. Similar to CatForce, but with a GUI.• gencols by Paul Callahan - Enumerates collisions between patterns (e.g. gliders and still lifes). Includes output filters to detect oscillators, spaceships, or successful eating of one pattern by another. Life evolution rule is hardcoded as a sequence of bit-parallel integer operations (so it's possible to change but not easy). Written in C.• gfind v4.8 by David Eppstein - Search program for low-period spaceships. Extends partial patterns a row at a time, keeping track of rows in all phases of the pattern. Includes modes for finding symmetric patterns. Written in C.• gsearch by David Eppstein - Performs a brute force search of all patterns fitting within a small rectangle. Evolves each pattern for a specified number of generations or until it repeats, grows too large, or matches a previously seen pattern. Recognizes spaceships, oscillators, unstable oscillators (such as queen bee and p90), replicators, and some puffers. Includes modes for finding symmetric patterns. Written in C.• Hersrch by Karel Suhajda (via archive.org - the original site is down) - Searches for open or closed Herschel tracks in Conway's Game of Life, using a database of known static and periodic track components. Written in C++.• JavaLifeSearch, or JLS - a Java port of lifesrc, with a GUI similar to WinLifeSearch, by Karel Suhajda.• lifesrc v3.8 by David Bell - Search program for oscillators. Written in C.• ofind v0.9 by David Eppstein - Searches for low-period oscillators. Similar to gfind, but extends patterns in all phases simultaneously rather than a single phase at a time, and includes special handling of stator cells. User can specify what spark the oscillator should produce, or how it should interact with neighboring patterns of other periods. Written in C.• Random Agar v1.1 by Gabriel Navasch - Looks for new Life oscillators, wicks, and agars. Generates random spatially periodic patterns, and runs them until they oscillate. Includes complete support for all possible symmetry types. Written in C++. Compiled Windows executable version by Nicolay Beluchenko is called RandAgar.• Paul Chapman's Seeds of Destruction Game - Manual search assistant for self-destruct circuitry, efficient glider-construction cleanups, reburnable fuses, etc. Java application.• WLS 0.71 (WinLifeSearch) - a Windows port of lifesrc, with a GUI to help with setup. Windows executables are included in the zip files; source code is on github.

Excellent! I see Dean has a p30 glider stream bridge. I tried to build one a couple of months ago, using XOR reactions. My first attempts failed, due to off-by-one timing errors, but I eventually achieved success. However, the resultant circuit was too large to be practical. I tried a different approach a few weeks ago that is much simpler, and possibly even more compact than DRH's method. If it is, I'll post it in the Patterns forum.

My new approach is quite simple. Each p30 stream is converted to a pair of p60 streams. The four streams just have enough room to cross safely. The p60 streams are then recombined into p30 streams.

Ugh... There's so many good search programs that use terminals/consoles and I don't know how to run them... I am a Java programmer. I wish someone could make a GUI version of these in Java, so everyone can use them, not just the computer savvy and people with the ability to compile C and C++.

Macbi wrote:Are there any descriptions anywhere of the quicklife algorithm? What optimisations does it use?

The Golly credits state that the quicklife algorithm uses some ideas from Alan Hensel. Maybe Andrew will post on this topic, but in the meantime, here's a link to a quick description of the algorithm Alan uses in his applet, plus links to the Java source code. http://www.ibiblio.org/lifepatterns/lifeapplet.html

Macbi wrote:Are there any descriptions anywhere of the quicklife algorithm? What optimisations does it use?

Tom Rokicki wrote the QuickLife algorithm (and HashLife, and all the other algorithms included in Golly, except for RuleTable which was written by Tim Hutton). I'm hopeless at bit-twiddling and Tom is hopeless at GUI stuff, so we make an excellent team.

I'd found similar pages to this dedicated to other life-like rules but lost them. There was one about 34-Life where the owner had managed to run a census on the rule (using a toroidal universe I think). Does anyone know and have a link to that site?